1. Technical Field
The invention and embodiments described herein generally relate to vapor generators, and, more particularly, to a dimethylmethylphosphonate (DMMP) vapor generator for high output applications.
2. Description of the Related Art
DMMP is used to determine the capacity that gas filters have for filtering toxic nerve agents without using toxic materials. Generally, vaporizing DMMP in large quantities (e.g., 100 cfm or more) has always been difficult and complete vaporization is next to impossible. In the late twentieth century, the concept of spraying DMMP into a length of heated pipe was first explored. Some of the earliest prototypes used an eight foot length of ¾ inch pipe heat traced to 350° F. by solar radiation where the pipe was held at a focal point in an eight foot parabolic trough reflector. Next, DMMP was sprayed into the end of the pipe and the nozzle air carried the DMMP mist through the pipe. The DMMP mist then vaporized before exiting the pipe. Data from this prototype was used later in the fabrication of the DMMP and agent vapor generator used in evaluating the filter developed for the V-22/Osprey vertical takeoff aircraft. One problem with this vapor generator was that the pipe was coiled and immersed in a tank of thermal heat transfer oil, which took hours to preheat.
Conventionally, no off-the-shelf vapor generator exists for vaporizing chemicals as heavy as DMMP which has the consistency of light-weight motor oil. Conventionally, DMMP vapor generators used for testing by the military generally suffer from chemical fallout, that is, not all of the DMMP that was injected into the test system vaporized. Thus, older test systems typically suffered from contamination issues, slow challenge concentration development, and could not be run clean. Most systems in use, utilize a spray nozzle. However, as mentioned above, there is a problem in that not all of the DMMP vaporizes. What does not vaporize stays in an aerosol or drops to the bottom of the test equipment such as a Q262 gas life test machine and must be drained away. Accordingly, a new and improved DMMP vapor generator that overcomes the limitations of the conventional solutions would be beneficial to the industry.